Piston for double-acting engines



Feb. 19, 1929.

T. D. BOWES PIsToN Fon DOUBLE ACTING ENGINES Filed April 22,v 1925 Harney Wn. u J \m, N WQ 2.1.., 5. L* 2 z 6 w M s FIG 4.

Patented Feb. 19, 1929.

UNITED STATI-:s`

PATENT OFFICE. f

THOMAS DAVID BOWES, GF C'YNWYD, PENNSYLVANIA, `ASSIGNOB., BY DIRECT .AND MESNE ASSIGNMENTS, 0F ONE-THIRD TO HUBERT C. VEBHEY AND ONE-THIRD T0 L. C. COIE, BOTH 0F PHILADELPHIA, PENNSYLVANIA.

PISTON FOR DOUBLE-ACTING ENGINES.

Application `filed April 22, 1925. Serial No. 24,966.

My invention relates toJ improvements in a piston for a double acting engine and particularly to a` piston for an internal combustion engine, in which the high temperature to which the Vpiston is subjected tends to cause the latter to crack. Heretofore pistons for this type of enginehave been constructed with end heads connected by a cylindrical wall of sufficient thickness to take the Working load of the engine, in either direction,

and transmit the load to the working parts two heads connected by a central member, or

piston rod, positioned axially between said heads and adapted to transmit the working load to which the heads are subjected; a further object is to provide each head with a cylindrical flange of sufficient length and weight to carry the piston rings, and provide a flexible drum between the heads, having its ends connected with the annular fianges of the heads, whereby the heads, or the piston rod, may expand freely without being held by rigid parts, and also forming a cylindrical chamber between the heads for a cooling agent; a still further object is to provide ahollow cylinder within the cooling agent chamber, thus Vreducing the capacity ofthe latter and reducing the weight of the cooling agent, due to the cooling agent chamber being reduced in size; and a still further object is to construct the piston rod in the form of a hollow tube adapt-ed to form a novel means for conveying the cooling agent into and out of the interior of the piston.

Referring to the accompanying drawing, Fig. 1 is a central vertical sectional view of a piston embodying a preferred form of Vthe invention, Fig. 2, is a transverse section on line 2-2 Fig. 1; Figs. 3 to 6, are sectional views similar to Fig. 1, drawn on a reduced scale, showing modified `forms of the invention. Y

In the accompanying drawing in which like reference characters refer to like parts, 1 and 2 represent opposite heads of a piston, which heads are provided with annular fianges 3 and Il respectively. Said flanges are each provided with grooves to receive the piston ring 6. Between the heads 1 and 2 is a central load carr ing member, or rod 8, which is positioned axially, an constructed suiiiciently rigid to take all the working load applied to the heads 1 and 2.. TheV member 8 is preferably formed integral with the heads 1 and 2, as shown in Fi .1, and arranged in axial alignment with `t e outer portion of the piston rod 9, adapted for transmitting the load to the operating parts of the engine, not shown in the drawing. i

A cylindrical member, or drum 10, is posi` tioned between the heads 1 and 2 and is adapted to form a yieldable construction between the heads. Said drum 10 also forms a sealed chamber 13 for the cooling agent.

The drum 10 is secured at its ends to the inwardly turned flanges 3 and 4 of the heads, by brazing or welding, thus forming watertight joints 14 and 15. The drum 10 is also constructed with a welded or brazed joint 16, shown in Fig. 2, which joint 16 extends longitudinally in relation to `the axis of the drum, and provides meansfor mounting the drum between the heads 3 and/1. j The drum 10 is referably made of thin metal and provided) with annular corru ations 12, to make it more flexible, so that t e piston rod 8 mayexpand longitudinally and the heads 1 and 2 may expand radially. Said drum 10, however, is formed of metal havin sutlicient thickness and rigidity to withstan the pressure to `which the cooling agent is subjected.

The central member, or piston rod 8, is of hollow or tubular formation and forms a. passageway 19 through which the cooling agent may pass into or out of the chamber 13. The cylindrical wall of the member 8 is provided with radial apertures 17 and 18 located adjacentto the inner surfaces of the heads 1 and 2. A pipe 2l) extends longitudinally through the passageway 19 formed in the piston rod 8. The inner end of the pipe 20 is secured in a web, or partition 21, formed iston in the piston rod 8, thus providing separate passageways through which the cooling agent may pass into and out of the chamber 13 of the piston.

The hollowcylinder 24 is provided within the chamber 13 of the piston for the purpose of reducing the size of the chamber 13. Said cylinder consists of end disks 25 and 26, formed upon the piston rod 8 and located adjacent to the heads 1 and 2, so that only small spaces are provided between the disks 25 and 26 and the heads 1 and 2, which spaces form the cooling agent chamber for the heads 1 and 2. The disks 25 and 26 are provided with inwardly projecting flanges 28 and 29 and a drum 30 is secured to the inner edges of the flanges 28 and 29 by welded or brazed j oints 32 and 38. A longitudinal joint 34 is provided in the drum 30, as shown in Fig. 2, by which joint the adjacent ends of the druni 30 are joined to form a cylinder. The drum 3() is provided with corrugations 31 so that it may yield due to the expansion and contraction ol"V the disks 25 and 26 and the parts associated with the same.

The inner cylinder 24 forms a sealed air chamber 35 which reduces the size oit the cooling agent chamber 13, thus reducing the weight of the piston, which without the cylinder 24 would be entirely lilled with the cobl ing agent which would add considerable weight to the piston. Said cylinder 24 reduces the chamber 13 yto relatively small spaces located adjacent to the inner surfaces of the piston through which the cooling agent may be circulated and forced in to contact with thc hottest parts of the piston.

Figs. 3 to 6, illustrate different construe tions which may be used in carryingn out my invention. Fig. 3 shows the head 40 made separately from the central member or piston rod 41, which latter is formed with a threaded portion 42 adapted to have the head 40 screwed thereon and tightened against a shoulder 43. The llexible drum 45 may be formed into a complete cylinder and assenr bled before the head 40 is secured in place. thus the longitudinal joint 16 as in the drum 12, shown in Fig. 2, will not be required. Fig. 4 shows a construction in which the head 46 is made detachable from the central rod 47 g Fig. 5 shows a construction in which the outer portion of the piston rod 49 is formed separately from the head 50 and secured thereto by bolts 51, and Fig. 6, shows a piston having both heads 40 and 46 made detachable.

A cylinder 52 formed of yieldable sheet metal is provided to reduce the size of thc cooling agent chamber, as shown in Figs. 3 to 6. The construction ot the piston having one head detachably mounted upon the piston rod, permits the cylinder 52 to be completed before the piston parts are assembled.

The cylinder 52 consists of inner and outer cylindrical Walls 54 and 55 and end members v56 and 57, which form a sealed chamber, haw

ing al central tubular formation adapting the cylinder to surround the piston rod. Said walls 54 and 55 are provided with corruga tions 59 and 60, which permit the metal form ing the walls to yield due to change ot temperature within the piston. The cylinder 52 is provided with spacing brackets 62 adapted to hold the cylinder in spaced relation with the inner walls of the piston, and thus form a cooling agent chamber oi small capacity located adjacent to the inner-walls of the piston, through which chamber the cooling agent is circulated in the manner above dcscribed. 4

l claim:

A piston for a double acting engine comprising, a piston rod, piston heads positioned in spaced relation upon said rod .adapted to take the working' load of the engine, annular flanges upon said head, a drum ot' yieldablc formation having its end edges secured to said flanges, disks mounted upon said rod positioned adjacent to the inner sur face of each piston head, annular flanges upon said disks positioned in spaced relation to the inner surface of said flanges upon the piston heads, a drum of yieldable formation having its end edges secured to said il anges upon said disks forming a hollow sealed cylinder, said rod being of hollow construction forming a longitudinal passageway for a cooling agent, and said rod having apertures formed through the walls thereof communicating with said passageway and with a cooling agent chamber 'formed between said piston heads and said cylinder.

In testimony whereol1 I aliix my signature THOMAS D. BOW'ES. 

